Multiple unit apparatus



May 30, 1944.

L. 0. REICHELT 2,349,882

MULTIPLE UNIT APPARATUS Filed May 25, 1942 2 SheetsSheet 1 EN 24 OIVE MOTOR 334 HUNT wo 0N0 DIG. GEN.

400 am 5 4 2 32 so; [Nd/D 3 7 INVENTOP L.O. PEI CHELT 8) ATTORNEY May 30, 1944.

L. O. REICHELT MULTIPLE UNIT APPARATUS Filed May 23, 1942 2 Sheets-Sheet 2 E A E J .m. 0 7- \.I/ n E 5 9 5 m ,K 5 kn V m3 1 m h 2 E, n E 0 3 m .m. g "h m o o m m w A TTOR/VEY Patented May 30, 1944 7,

5T OFFICE- MULTIPLE -,UNIT APPARATUS Lester 0. Reichelt, Cranford, N. 1., assignor to Western Electric Company, Incorporated, New

York, N. Y., a corporation of New York Application May 23, 1942, Serial No. 444,285

6 Claims. (Cl. 57-100) This invention relates to multiple unit apparatus, and more particularly to apparatus for combining strands into multiconductor electric cables or cores for such cables.

The manufacture of cables or cable cores con sists essentially in simultaneously longitudinally advancing a plurality of suitable strands and rotating the plurality about an axis in the line of advance to intertwist the strands together. To do this, one usual method is to mount a plurality of supplies of strand, e. g. spools, reels or the like, in a rotatable support which is rotated at constant speed while the strands are drawn of! together in the direction of the axis of rotation through a stationary compacting die, and the cable or core thus formed is then taken up on a reel, spool or the like whose axis of rotation is stationary and at right angles to the advance of the cable. Another method is to hold the plurality of supply reels stationary in position and cause the axis of the take-up reel to rotate on the line of advance of the cable. In either cs-ses there are two principal motions involved, the linear longitudinal advance of the plurality of strands, and the rotation of the plurality about the line of longitudinal advance which effects the intertwisting together of the strands, the latter motion being efiected in the one case by the rotation oi the strand supplies and in the other case by the rotation of the strand take up. A third method consists in providing a rotating flier to effect the rotation of the group of strands, the flier being positioned to rotate about either the group of strand supplies or the take-up means. In whichever way the cabling is done, the apparatus to do it will include an element rotating about an axis parallel to and usually coincident with the line of advance oi the combined or ca- "bled strands, and an element rotating about an axis at right angles to the advancing cable. The former of these two elements performs the function of intertwisting the strands together and the latter the function of advancing the cabled strands or of winding the cable up for storage or both. The former element may be a rotarily driven cage in which strand supply reels are mounted, or it may be a flier rotating about a stationary group of such reels, or about a take-up reel, or it may be a rotarily driven frame in which a cable advancing means or storage means or both are mounted to rotate with the frame. The latter element, the one effecting the longitudinal advance of the strands and cable, may be a capstan operating independently or in connection with a take-up reel, or it may be a simple reel which is 55 driven both to advance and take up the cable.

In any event the angular twist per unit length, or lay, of the cable is governed by the ratio of the rotary speed of the twisting element about the axis of the cable the rotary speed of the cable advancing element no matter which 0! the methods or apparatus described employed. Furthermore, the regularity of the lay of the cable depends upon the constancy of this ratio and not upon the absoiute values of the two speeds. Because of the forces and stresses involved, cabling machines are large and massive, especially as to the principal rotating elements. The control of the speeds of these elements and the maintenance of their constant ratio, especially during acceleration and deceleration, the maintenance of ten.- sion in the strands and cables during periods of stoppage, the proper synchronization of auxiliary devices, e. g. means to serve a binding strand about the inter-twisted conducts: strands, and the like functions, present dimcult probf-lrns because of the masses, inertial forces and naeci for accuracy of control involved. The same problem arises in other kinds of multiple unit apparatus, where cooperating but t therwise inde endent elements must be kept carefully controlled in r" 0- tion retentive to each other.

An object of the present invention is to provide, in multiple unit apparatus and particularly in cabling machines, an erhcient, reliable and sensitive system of driving and controi means effective substantially automatically to maintain the geometric interrelations of strands beim? operated on by the apparatus substantially constant under all conditions of'operation of the apparatus, whether at rest. in acceleration, in full operation. or in deceleration.

With the above and other objects in view, the invention, in a cabling machine having a plu- -rality of independently powered cooperating units, e. g. a motor driven iiierand a motor driven take-up reel, may be embodied in means to actuate and control the several power means and comprising means to drive one unit, an electric motor driving another unit, a vacuum power tube to supply power to the said motor, a phase shifting device to control the output of the vacuum tube, and a differential device driver. by the two units and in turn driving the phase shitting d5.-

vice to modify the speed of the motor.

Other objects and features of the invention wiil appear from the following detailed description or one embodiment thereof tasen in connection with the accompanying d1 swings, in which the same reference numerals are applied to'identical parts,

in the several'figures. and in' which Fig. lie a.

diagrammatic representation of the electrical devices and circuits comprised in. the. driving" and control means, constructed in accordance with;

the invention, of a-machine having a plurality of motor driven, cooperating units; and

Fig. 2. is a diagrammatic. representation of a. cabling machine to which may be applied the control system illustrated in Fig. 1.

The apparatus disclosed in Fig. 1 as an illustrative embodiment. is i the driving and control system for a cabling machine. The relevant me.-

chanical features of one suitable type of suchmachine areshown in Fig. l in order to illustratethe means to drive a take-up; As adjuncts theremay also be devices such as th booster driven by the motor 9, and the serving head driven by the motor l0. Thus, for illustration of the invention. let there be assumed a machine, as shown in Fig. 2, having a main driving motor to drive a flier,

related auxiliary motors to drive a booster andv a.

serving head, and a wholly independent motor to drive a take-up. The Fig. 1 of thedrawing herein discloses diagrammatically and in detail the network of circuits which supplies power to. and effectuates the necessary control of these units of the machine. I

The machine control comprises an arrangement'in which the speed of the main driving motor and related. auxiliary motors is controlled by varying the field of a constant speed sepa-- rately excited D. C. generator by which these motors are driven. In combination with the machine control a separately excited D. C. shunt motor drives the take-up truck by a means hereinafter explained wherein the take-up truck speed is held in proper relation to that of the cable and machine to hold the lay constant. The drive system consists of a D. C. shunt generator I driven by a constant speed motor 2. The field 3 of the'generator l is separately excited from D. C. mains 300 and 3M and its voltage output is controlled by the resistor bank 4 of a motor operated rheostat 5 in series with the field 3 across the D. C. outside supply mains 300 and possible, by the regulation of the generator field.3.'

from .thefllament sides. I8, I 9' and; 2030f rectifier tubes 2|, 22 and.23 and the neutral of athreephase. A. C. transformer 24- through" lines 52L 522, 523, 520v and-.524.- The transformer 24 isconnected to suitableathree-phase A; C. mains 500; 50! and 502iand;deliversA; C. power through the lines 506, illz'l and 508,- contacts. 38, 39 and 40 of a. magnetic switch'31 and lines-509; 5H)

anda,5.ll.to the plates:25, .26 and 21 of the tubes 2|, 22" and, where it is changed to D. C. power and delivered through the lines 52!, 522, 523

and 524 to the motor IS.

A means is provided for maintainingathe speed of the take-up unit in-properrelation tothe speed of the revolving flier to maintain the'cable speed constant. This is accomplished by means of a wheel 23 riding onthe: cable I23- being made in the machine driving one member of a differential 29: A second member of the. differential 29 is driven at constant speed1by the revolving flier through a shaft .43 and: the third member drives a shaft 30 to change-the speedv of the take-up motor l6. 'Operation of this-.difierential is explained in full detailin Patent No. 2il'7l,993.

Rotation of thedifierentlalj shaft 3ll causes rotation of the rotor 3| of a conventional threephase device 32, excited from-.the transformer through lines 503, 504 and'555; to induce an out-of-phase voltage in the stator 33 which is transmitted throughlines 525, ,528 and 521 to the grids 34, 35 and 36 of the tubes 2i, 22'and 23. Therefore, when diflerential system 29.:calls for. a speed change .otthe take-up. truck motor IS, the shaft 30 changesztheposition of the rotor.

3| to induceavoltage of'proper. phase in the stator and biasthe tube grids'as previously the magnetic switch 31, interposedv in lines 506,

501 and 5fl8aand 509; 5! and 5, respectively,

connect and disconnectthe take-up motor Hi from its electrical source 24, as' called for'by normally allow free rotation .of the core unit in a direction opposite to .the advancement direc- 30l. The armature of the generator I is in parallel arrangement through lines 400, 40! and 402 and the contact 6. of a solenoid operated.

switch 1 and further through lines 405 and 404 and a contact 4| of a switch 42 with a flier drive motor 8, a booster motor 9 and a serving head motor 10. Themotors B, 9 and i0, which are of the D. C. shunt type, are separately excited through fields ll, [2 and I3 from D.- C. mains 300 and 30L As the voltage delivered by generator l is a function of the amount of excitation in the generator field 3, the speed of the motors 8, 9 and i0 is also a function of the voltage present across field 3' as controlled by the resistor bank 4 of the rheostat 5. Motors 9' and ill have variableresistors I4 and IS in series with their respective fields l2 and I3 to give additional speed variation above the maximum made tion of the cable due to the back pull of the tension from the wire supplies. To overcome this pull back or backlash a. pawl 65 is provided to catch in a ratchet. wheel connected to the drive shaft I83 of the'take-up. drive motor l6; For-practical reasons the-pawl: must be disengaged from the ratchetwheel while the machine is operating abovejogging speed' and: loading and unloading the core unitinto the strander. A solenoid 44 is provided for this purpose, receiving its energization through A. C. lines50l, 532, bars 45 and 46 ofthev rheostat 5 and a slidable contact connecting bars 45 and 43 on the rheostat 5, the-function of which will be here-- inafter described, and thencethrough line 528' to line5fl0. A-- separate switch .48, through acontact 49, also allows of independent energization of the solenoid 44.

v Means is also provided for holding themachine at rest by a conventional brake (not shown) acting on the shaft of the flier drive motor 8 and actuated by a solenoid The control further comprises a starting switch 52, having instantaneous closing contacts 53 and 54, a delayed closing contact 55 and a delayed opening contact I84, said switch being controlled by a push button station 58 consisting of a start 51 and stop 55 portions, and the maintaining contact 58 of the switch 48. A jogging switch 59 having two contacts 58 and 8|, is controlled by a push button station 62. There are also a brake release switch 83 having a closing contact 54; a stopping switch 58 having instantaneous closing but delayed opening contacts 51 and 58; a take-up holding switch 59 having an instantaneous closing butdelayed opening contact 18; a load-run switch 42 having closing contacts 4|, II, 12 and 13 controlled by a push button station 14 having make and break buttons 15 and 15. The complex switch and rheostat 5 is operated by a motor 11 with two electrical fields "I and 19 so connected that their individual separate excitation allows motor operation in either direction. The motor 11 drives through a shaft 92 and bevel gears 88, a shaft 8| having a screw thread cut therein. A crossbar 82 engages the threaded shaft 8| so that revolution of shaft 8| causes travel of the bar 82. The bar 82 has mounted therein brushes 84, 85, 85, 81, 88 and 89 connected in pairs by wires 41, 98 and 9| respectively. Wire 41 through brushes 84 and 85 connects the bars 45 and 45; wire 98 through brushes 88 and 81 connects the bar 94 and the variable resistor 4 and the wire 9| connects the bars 95 and 95, and also the bars 91 and 98 when the rheostat is in one extreme position. Limit switches 93 and 99, designated as upper and lower respectively, are operated by projections' I88 and IN on the bar 82.

The above described complex of devices must function together as hereinafter explained to accomplish the following.

The machine when starting must run at a very slow speed for several revolutions until the takeup unit gets started without uneven operation; the machine must then accelerate uniformly until maximum machine operating speed is reached, where it must operate at constant speed. In stopping the machine must decelerate uniformly to a point of very slow speed, which speed must be maintained for several revolutions to allow the machine inertia effect to catch up with the regen erative braking brought into action in the now driven motors and then the machine must stop and several seconds later the take-up tens on be released. A further necessity is that while the machine is being loaded, the running circuit shall be inoperative and the booster, serving head and take-up motors disconnected from their supply sources.

This is accomplished as follows. Five condit ons of machine operation will be described, starting, running, stopping, jogging and loading.

To operate the machine it is assumed that power has been applied to the motor 2 and it is operating the generator I at the required speed and that lines 388, 38I, 588, 58I and 582 are energized also. Further, it is assumed that the control is in a normal start pos tion, that is switch 42 has been closed by the operation of the button 15 which completes an electrical circuit from line 38I, through line 383, buton 15, line 384, button 15, line 385, the coil of 42 and line 385 to line 388. This operation closes contacts H, 12, 4| and I3 and the coil of switch 42 is maintained energized after the breaking of button 15 by the release of finger pressure, by a circuit from line "I, through line 383, button I8, line 381, contact 13, line 388, coil of 42, line 385 to line 388. The bar 82 of the motor operated rheostat 5 is then in its normally off position spanning bars 91, 98 and 94, resistance 4, bars I82 and I83. Also, the button 58 of the switch 48 is closed.

Starting is then accomplished by momentarily closing the start button 51 which completes an electrical circuit from the line 388, through the line 389, the closed buton switch 58 of the switch 48, the line 3I8, the coil of switch 52, line 3| I, the closed contact II of the switch 42, line 3I2, button 51 of the station 58, line 3|3,

. the normally closed buton 55 also of the station 58 and the line 3|4 to the line 38I. Thus switch 52 is closed, immediately closing contacts 53 and 54. Contact 54 establishes a holding circuit for the switch 52, after button 51 is released by completing a circuit from button 58 through line 3|5, contact 54, and line 3|5 to line 3I2 and thence to line 388 as hereinafter enumerated. The closing of contact 53 completes a circuit from line 3I5 through contact 53, line 3|1, line 3|8, the coil of switch 59, lines 3|9 and 328 to line 388 to close the switch 59, thereby closing contacts 58 and 8|. Closing of the contact 58 causes a circuit to be completed from the line 388, through line 328, contact 58, line 32I, line 322,, the coil of switch I, line 323, and line 324 to line "I, and also from line 322 through line 325, the coil of switch 53 and line 324 to line 38|.

Closing the contact 5| completes an electrical circuit from line 588 through line 528. line 525, the previously closed contact 12 of the switch 42, line 538, contact 5|, line 53I, the coil of switch 31 and line 532 to line 58I. The effect, therefore, of closing contacts 5| and 52 is to energize and close the switches 53, I and 31. The closing of the switch 83 closes a contact 84 to complete an electrical circuit from the line 388, line 326. the releasing solenoid 5| of the brake. the l ne 321, the contact 54, the line 328 to line 38l. This releases the brake from the main drive motor 8 and coincidentally motors 8, 9 and I8 are connected electrically through the closing ofthe switch I and the take-up motor I5 is connected electrically to its source of energy through the closing of switch 31 as hereinbefore explained. Thus the mach ne starts operation and runs at a slow speed because of the resistance 4 of the rheostat 5 connected in series with the field 3 of the generator I, this circuit being established from line 388, through line 329, resistance 4, brush 85, connector 98, brush 81, bar 94, line 338. field 3 of the generator I, and line 33I to line 38I, is at a decreasing maximum.

Returning now to the operat on of switch 52, as previously stated contacts 53 and 54 close instantly, but contacts 55 and I84 are so arranged that they are delayed, say five seconds for purposes of demonstration, in closing and opening respectively. Therefore the machine runs at very slow speed for five seconds until the contact 55 closes. cuit is completed from the line 388, through line 332, the armature of the series motor 11 and its field 19, 1"ne 333, contact 55, line 334. limit switch 93 of the rheostat which is closed under the condition being described, line 335 and line 33I to the line 38I. The establishment of this circuit causes operation of the motor 11 as hereinbefore described to turn the screw shaft 8| On the closing of this contact 55 a cirwhich causes the nut 63 and the bar 92 of which it is a part to move away from its original position. This motion of the bar 62 continues until it arrives at the other extreme or normal maximum machine speed position when the projection IOI on the bar 82 opens the limit switch 19 and operation of the motor discontinues. As the bar is moving uniformly, the portion of the resistance 4 in series with the generator field 3 becomes uniformly less and less until full field strength is present in the field 3 of the generator I. This causes full voltage output of the generator to be impressed on the motors 8, 9 and I0, and the maximum cont nuous operating speed of the machine is obtained and maintained until it is desirable to stop the machine.

Coincident with the described movement of the bar 82, connections across 91 and 99 and I02 and I03 are broken and connections are made across 96 and 96 and 45 and 46 respectively. The connection 95 and 96 completes an electric circuit from line 300 through line 336, the coil of the switch 66, line 331, brush 89, connection 9I, brush 88, line 336, line 335, and line 33I to line 30I to operate the switch 66 and thereby close its contacts 61 and 66. The contact 61 completes an electric circuit from the line 300 through line 336, contact 61, line 339, the coil of a switch 69, line 340, l ne 324 to line 30I to operate the switch 69 and close the contact I0.

The closing of the contact 66 of the switch 66 establishes a parallel arrangement with the contact 60 of the switch 59, completing a secondary circuit from line 300, through line 336, theclosed contact 68, and line 322 through the coils of switches I and 63 to line 30I as hereinbefore explained. The closing of the contact I of the switch 69 establishes a parallel arrangement with'the contact 6| f the switch 59, to complete a secondary circuit from the line 500, through line 528, line 529, line 537, the closed contact 10,

' line 536. line 53l, the coil of switch 31, and line 532 to line Bill. The switches 66 and 69 are of the delayed opening type and establish holding- In circuits for the switches I and 63 and 31 respectively, the definite functions of which are hereinafter explained.

Returning now to the connection across the bars 45 and 46 which establish a circuit from line 500, through line 528, the coil of the solenoid 44, line 533, bar 46, brush 95, connection 41. brush 84, bar 45, and line 532 to line 50I. This ener izes the solenoid 44 to release the pawl 65 on the take-up unit drive shaft which is desirable during operation of the machine as hereinafter explained.

Now assume that the machine is operating at normal maximum speed and it is desired to stop the machine. This is accomplished by momentarily closing the stop button 56 of the station 58. The circuit through the switch 52 is interrupted through the circuit path hereinbefore enumerated, and contacts 53, 54 and 55 are opened and contact I04 is closed. The opening of contact 54 interrupts the circuit of the coil of switch 59 through a path hereinbefore enumerated and contacts 60 and 6I are Opened which would tend to interrupt the circuits to switches I, 63 and 31 were it not for the parallel holdingin arrangements through switches 66 and69 as hereinbefore explained. Coincident with these operationsthe closing of the contact I04 of the switch 52 causes a circuit to be completed from line 300 through line 3I2, the armature of the motor 11 of the rheostat 5. the motor field I8.

line 3, the upward travel of the bar 82, and line I to line I. 'This causes operation of the motor 11 to turn the screw 8| in a direction to advance the bar in the reverse direction to that of its former motion. This action causes an increasing amount of the resistance 4 to be connected in series with the field 3 of the generator I with a coincident reduction in generator output voltage to effect deceleration of the motors 8, 9 and I0 by regenerative means. Deceleration of the take-up motor is also accomplished by reduction of its input voltage by the action of the differential 29, depending on the moving cable and the machine deceleration.

coincidental with and essential to the regenerative braking as the bar 82 moves downward is the maintenance of the holding circuits on the switches I, 63 and 31 by the switches 66 and 69 through the bars 96 and 96 of the motor operated rheostat 5 as hereinafter explained. Therethrough the motors 6, 9 and I0 are held in connection with the generator I until the bar 82 i; in its extreme position across the bars I02, I03, 91 and 98. At this point the limit switch 99 is bpened by the projection I00 on the bar 62 and the motor circuit is interrupted and the motion of the bar 62 stops.

Because the revolving parts of the machine 4 have considerable inertia and the slowing down 'running of the take-up motor I6.

of these parts lags behind the speed corresponding to the voltage output of generator, immediately stopping the machine when the bar 92 reaches its extreme point by applying the brake SI and disconnecting the motors 8, 9 and I0 would cause a bad jar and an undesirable over- Therefore. switches 66 and 69 are of the delayed action type so that when the bar 62 passes oil the bars 95 and 96 of the rheostat 5, the circuit to switch 96 is broken but because the contacts 61 and 36 are delayed opening the machine runs for say three or four seconds at very slow speed, which allows the inertia effect of slowing down to dissipate itself and when contact 69 opens, the circuits of switches I and 63 are broken, opening contacts 6 and 34 to disconnect the motors 8, 9 and I0 from the generator I and set the motor brake through the solenoid 5E. The opening of the contact 61 of the switch 66 interrupts the circuit through the switch 69 which after a time delay of, say one second, allows contact '10 to open and take the take-up motor I6 off the line through the interruption of the circuit to the switch 31. Thus the take-up tension in the cable being made is maintained for a few seconds after the machine is stopped. From this point on stalled tension in the cable being made is maintained by the pawl 65 on the core unit motor shaft, this pawl having been brought into operation by release of the solenoid 44 by the bar 82 breaking oil the bars 45 and 46 when the bar 82 reaches its extreme or off position.

When take-up reels are being removed from the machine a release of the pawl 65 is desirable and is effected by the closing of th button 49 of the station 46, which, through lines 534 and 535, is in parallel arrangement on lines 5I2 and 532 with the bars 45 and 46, of the rheostat 5. The station 48 is of the maintaining type and coincident with the depression of th Joutton 49 the circuit through the button 50 is broken so that operation of the machine is interrupted by the opening of lines 309 and M0.

It is desirable at times to-operate the machine at a jogging or an inching speed. This speed is obtained with the full resistance 4 of the rheostat 5 in series with the field l the generator land the bar 82 of the rheostat I in its on! position. This is accomplished by depressing; and holding down the jog button 52 which completes a circuit from line 300, through line fllliline iii, the coil of switch 59, line Ill, bar ll, brush ll, connect-ion 9i, brush 88, bar 91 of the'rheostat 5, line 3, button 62, and line 3 to line "I. This causes the operation of the switch 59 to close its contacts 60 and '61, to close switches I, 61 and 31, which allows the machine to operate at slow speed as hereinbefore explained. Releasing the button 82 breaks the circuit to'switch I and the machine stops. Jogging is prevented when the machine is operating at any speed above this slow speed because the bar 82 of the rheostat 5 in moving upward breaks the Jog circuit by passing oil the bars 91 and '98.

Assume now that the supply of the machine is to be loaded. Under this-condition'the main motor must remain connected, but the motors l,

plained. On completion of the loading operation the momentary depression of the button I! of the station H resets the switch for running operation oi the machine through the closing of its contacts H, 12, and I3.

Reduced to its lowest terms, the invention would comprise the motor I driven at constant speed, the motor l6 driven by the" tubes Ii, 22

and 23, the phase shifter 32 controlling the output of the tubes, and the differential 2! driven at one side by the motor I (through mechanical means not shown) and at the other side by the motor l6 (through the cable drawn along by this motor driving the take-up) and in turn driving the device 32 to modify the output or the tubes and hence the speed of the motor I as required to keep the two motor speeds in constant relation to each other. Generalizing this somewhat, thesingle motor I may become a plurality of motors, as in the particular illustration described (I, 9 and Ill), interrelated (by their common power source I) to run synchronously; and also the power lines 520 and 524 fed by the.tubes could feed more than one motor l5, ln series, in parallel, or in multiple, which motors then would form a second plurality of interrelated motors. Thus in any apparatus or machine having at least two groups of motors, interrelated mutually in each group but independent oi-each other as groups, control of thegroups relatively to'each other may be had by supplying power to at least one group strand twisting member .and'a rotatable strand" advancing member to mtertwist a' 'pluralitybf strands into a cableby the coopcrat'iveaction of the two members, ineansto ifotatelthesstrand twisting member, anfelctric rnotor to rotate the strand advancing member-Qava'cuum power tube to supply currencto' the mowe -arse the-same.

and means driven by the strandjtwisting member and by the cable being formed "in'the machine anden'ective to modify the-output of the vacuum tube to the motor; in accordance with variations in the ratio oi' the speedof the rotating strand twisting member to the longitudinal speed or advance of the cable, in combination with means to hold the strandadvancing member against reverse rotation during periods or swppage and thereby maintain in the cable being'made the tension necessary to keep the vacuum tune output modiiymg means accurately eifective during -accelerauon and deceleration 01 too machine.

2. In a cabling machine having a rotatable strand twisting member and a rotatable strand advancing member to mtertw'ist a plurality of strands into a cable by the cooperative action or the two members, means to rotate the strand twisting member, an electric motor to rotate the strand advancing member, a vacuum power tube to supply Cllllfillt'tu the motor to drive the same, and means driven by the strand twisting member and by the cable being rormed in the machine and eiiective to modify the output of me a vacuum tube to the motor in accordance with through vacuum tubes, controlling the output of 1 these tubes by a suitable adjustable electrical device such as the phase shifter 32, and providing a diiierential device driven by the two groups of motors and connected to drive the adjustment of the tube output control device.

Since, in the case of the particular kind of machine used to illustrate the invention, and for which the invention is particularly advantageous, namely a cabling machine, the maintenance of tension in the cable during acceleration and deceleration and during periods of stoppage is important to the satisfactory operation or the wheel 2' and hence of the differential and thus of the 3. In a cabling machine having a rotatable strand twisting member and a rotatable strand advancing member to intertwist a plurality of strands into a cable by the cooperative action of the two-members, an electric motor to rotate me" strand twisting member, an electric motor to rotate the strand advancing member, a vacuum power tube to supply current to the second named motor to drive the same, and means driven by the strand twisting member and by the cable being formed in the machine and effective to modify the output of the vacuum tube to the motor in accordance with variations in the ratio of the speed of the rotating strand twisting member to the longitudinal speed of advance of the cable, in combination with means to apply full power at once from the vacuum tube to the second named motor and to supply gradually inadvancing member to intertwist a plurality of strands into a cable by the cooperative action of the two members, an electric motor to rotate the strand twisting member, an electric motor to rotate the strand advancing member, a vacuum power tube to supply current to the second named motor to drive the same, and means driven bythe strand twisting member and by the cable being formed in the machine and effective to modify the output of the vacuum tube to the motor in accordance with variations in the ratio of the speed of the rotating strand twisting member to the longitudinal speed of advance of the cable, in combination with means to apply full power at once from the vacuum tube to the second named motor and to supply gradually increasing power to the first named motor while the machine is being started and to supply gradually decreasing power to the first named motor while continuing to apply full power from the vacuum tube to the second named motor while the machine is being stopped.

5. In a cabling machine having a rotatable strand. twisting member and a rotatable strand advancing member to intertwist a plurality of strands into a; cable by the cooperative action of the two members, an electric motor to rotate the ually decreasing power to the first named'motor while continuing to apply full power from the vacuum tube to the second named motor while the machine is being stopped and means to hold the strand advancing member against reverse rotation during periods of stoppage and thereby maintain in the cable being made the tension necessary to keep the vacuum tube'output modifying means accurately effective during acceleration and deceleration of themachine.

6. In a cabling machine having a rotatable strand twisting member and a rotatable strand advancing member to intertwist a plurality of strands into a cable by 'the cooperative action of the two members, an electric motor to rotate the strand twisting member, an electric motor to rotate the strand advancing member, a vacuum power tube to supply current to the second named motor to drive the same, and means strand twisting member, an electric motor to rotate the strand advancing member, a vacuum power tube to supply current to the second named motorto drive the same, and means driven by the strand twisting member and by the cable beingformed in the machine and effective to' driven by the strand twisting member and by the cable being formed in the machine and effective to modify the output of the vacuum tube to the motor'in accordance with variations in the ratio of the speed of the rotating strand twisting member to the longitudinal speed of advance of the cable, in combination with means to apply full poweriat once from the vacuum tube to the second named motor and to supply gradually increasing power to the first named motor while the machine is being started and to supply gradually decreasing power to the first named motor while continuing to apply full power from the vacuum tube to the second named motor while the machineis being stopped and a ratchet wheel on the strand advancing member and a pawl to coact therewith to hold the strand advancing member against reverse rotation during periods of stoppage and thereby maintain in the cable being made the tension necessary to keep the vacuum tube output modifying means accurately effective during acceleration and deceleration of the machine.

- LESTER O. REICHELT. 

